This invention relates to flexible polyurethane foams, more particularly to flexible polyurethane foams prepared using poly(alkylene carbonate) polyols.
Conventional polyurethane foams have usually been prepared by reacting a polyether polyol or a polyester polyol with a polyisocyanate in the presence of a blowing agent. Unfortunately, these foams have very poor solvent stability; that is, they tend to readily degrade, swell or dissolve in the presence of a variety of solvents, particularly organic solvents. This property severely restricts the range of utility for such foams, since they cannot be used in the presence of organic solvents.
Poly(alkylene carbonate) polyols (hereinafter PAC polyols or PACs) are hydroxyl-terminated polymers containing repeating carbonate linkages. PACs are readily prepared by reacting an oxirane such as ethylene oxide with carbon dioxide and/or a cyclic alkylene carbonate in the presence of an initiator to form a polymer having an equivalent weight from about 100 to about 3000. Such PACs typically contain about 2 to about 33% (depending on the equivalent weight and choice of initiators) by weight of repeating --COO-- units, and a significant proportion of ether linkages.
As hydroxyl-terminated polymers, PACs have been suggested for use in preparing polyurethanes. See, for example, U.S. Pat. No. 3,764,457, in which a polyurethane elastomer-containing laminate is disclosed. Because of the low cost and good properties of the PACs, it would be desirable to provide a polyurethane foam prepared therefrom.
It would also be desirable to provide a polyurethane foam which has improved solvent resistance as compared to polyurethane foams which are prepared from polyether polyols or polyester polyols. It would also be desirable to provide a polyurethane foam which has good inherent antistatic properties.